It was March A.D. 20. The Matronalia, the Festival of Juno the Great Goddess that celebrated Roman motherhood, had passed. Piso was back at Rome, and his accusers had prepared a case against him. Just a day after Piso had returned home to his house overlooking the Roman Forum, the Senate convened at the Curia, the Senate House, on the northeastern side of the Forum, to decide whether Piso should be called to answer charges in relation to the death of Germanicus. As the Senate benches filled before dawn, Piso took his place with his fellow senators.

Once this preliminary hearing got under way with the sun rising behind the Capitoline Mount and the Senate’s water clocks beginning to trickle into the first hour of the day, the senator Fulcinius Trio came to his feet. Trio, an experienced lawyer, was infamous as a man who informed on his fellow senators, telling Tiberius if he overheard them speaking treasonously, or betraying them if they committed adultery or any number of other crimes. Tacitus also described Trio as a man who liked notoriety and who recklessly made enemies in the process.¹ Trio now sought permission from the presiding consul, Aurelius Cotta, to launch a prosecution against Gnaeus Piso for the murder of Germanicus.

The senators Publius Vitellius and Quintus Veranius, the two generals and friends of Germanicus who had been in the East with him, quickly objected, and were supported by other friends of Germanicus. This prosecution was not Trio’s role, they declared. They said that they intended to report to the House that they had instructions from Germanicus, received from him on his deathbed, to personally pursue a trial of Piso for murder, and to personally give evidence in that trial as men who had been with Germanicus at the time of his death. How, they asked, could Trio possibly conduct a prosecution when he had not even been in Syria at the time of the murder?

In the light of this objection, Trio now withdrew his original request and sought the consul’s permission to conduct a prosecution against Piso for crimes he would allege Piso had committed while governing Farther Spain earlier in his career. This sounded odd and unnecessary, but the consul Cotta proposed that the emperor be asked to undertake an inquiry into whether any prosecution should be launched against Piso, be it for the murder of Germanicus or on the charges brought by Trio. Not even Piso objected to this, and the Senate unanimously voted in favor of the proposal. The consul duly wrote to the emperor to advise him of the Senate’s resolution.

When Tiberius received the Senate’s request, he summoned the accusers, the accused, and a small number of his own most intimate friends from among the senators, to attend a meeting at his palace. Tacitus says that this suited Piso, as he felt he would receive a fairer hearing from a single judge than from hundreds of senators. He was also confident that Tiberius would support him, because, in Tacitus’s words, Tiberius was “entangled in his mother’s complicity.”² Tacitus believed that both Piso and Livia had played a role in the murder of Germanicus, but he was not convinced that Tiberius was also guilty.

There was a chamber within the Palatium complex standing high on the Palatine Hill overlooking the bustling city where Tiberius conducted audiences and hearings. This semicircular imperial basilica would survive, as a shell, to modern times. Here, seated on a raised tribunal, Tiberius listened to the accusations leveled against Piso by the companions of Germanicus, and to a plea of innocence from Piso himself. Tacitus says that Tiberius was well aware of the rumors that he himself was implicated in the murder.³ With these rumors in mind, he decided to send the case back to the Senate, recommending that the Senate conduct a trial, with charges to be preferred against Piso for defying Germanicus’s orders, for making civil war, and for murdering Germanicus. In addition, Piso’s wife, Plancina, was to be charged as Piso’s accomplice in the murder of Germanicus, and Piso’s son Marcus was to be charged with making civil war in Cilicia alongside his father. As Cassius Dio was to write, in this way, by bringing Piso and members of his family to trial in the Senate, Tiberius set out to clear himself of the suspicion that he had been involved in the destruction of Germanicus.

A trial in the Senate meant that it would be held out of the public gaze. In criminal trials held before a panel of judges in the Julian Basilica, Rome’s courthouse, the public galleries of the four adjoining courtrooms were always packed with onlookers, male and female. Many of these audience members sitting in the mezzanine galleries were paid by one side or another to applaud or heckle the various advocates. Now, with a trial in the Senate House, the emperor would be able to control proceedings, for there was no public gallery in the Senate. Members of the general public were banned. This also allowed Tiberius to personally attend its sittings. Now, too, every senator could share the responsibility and the blame for this murder trial that the people had been baying for, and could share responsibility for the verdict.

Tiberius decreed that the prosecution be given two days to present its case, and, after an adjournment of six days, the defense would occupy three days. As was usual practice, the Senate would sit on each of those days from dawn until dusk. Critics of the emperor would wonder why Tiberius had given the prosecution less time than the defense. The defense was presumably being allocated more time because there were three defendants, and because two different prosecutions were to level charges against Piso—in addition to the Germanicus case, the emperor also was permitting Senator Trio to make his case about Piso’s alleged improprieties in Spain. But it was generally believed that two days should be enough to prove the case for murder against Piso.

Torches glowed throughout the city. In the Forum, it was as if daylight had come. The sun had yet to rise, yet the day on which Piso’s trial was to commence had begun. Not just all of Rome but also all of Italy was talking about the trial, which, says Tacitus, was conducted “amid the excitement of the entire country.” No business would be conducted in the city while the trial was in progress. Rome had once more come to a standstill.

In the torchlight, the Forum was packed with tens of thousands of people, all facing the squat, rectangular Senate House below the Capitoline Mount. The Senate House of A.D. 20 still stands today. It had been rebuilt by Julius Caesar after its predecessor had been burned down in riots leading up to the civil war that brought Caesar to power. Centuries later it would be given a face-lift by the emperor Diocletian, but the Curia we see today still looks much as it did on the day the Piso trial began.

The Praetorian Guard was out in force. Its job included providing security to the Senate on sitting days, keeping the public out of the Senate House, and searching every senator for weapons before allowing him to enter its portals. The Guard’s stony-faced Italian soldiers surrounded the Senate House in solid ranks, each man with one hand on the hilt of his sheathed sword, the breeze of the last days of winter ruffling their blood-red cloaks. A hush hung over the crowd. Many citizens were moodily silent; others spoke in hushed voices, sharing “secret whispers against the emperor,” says Tacitus.

Inside the Senate House, the senators, wearing their official purple-bordered white togas that came out only for official occasions, were taking their places. No females were present; all senators were male. They were talking animatedly, their voices echoing around the shiny marble floor and soaring walls. This practical building was 220 feet long and 80 feet wide, with small windows set high in its tall brick walls to admit light. A series of large double doors, closed now, were set in three of the four walls. The Curia’s ornate wooden ceiling, built in a checkerboard pattern, hung 100 feet above the senators’ heads. Three low marble tiers rose to the left and to the right of the central walkway. These tiers were occupied by the benches of the members of the House.

The first row of benches on each side was occupied by former consuls, who were the first to speak in debates. Among these front-bench men today was Germanicus’s friend Vibius Marsus. Less senior senators, praetors, and other middle-ranking officials sat in the second row. The least senior members of the House, men recently admitted to the Senatorial Order, occupied the back benches. Among the latter was the redheaded Publius Suillius Rufus, who had been Germanicus’s quaestor. As a former quaestor, Suillius had automatically gained entry to the Senate after serving Germanicus.

On the highest of the three low tiers facing the main doors sat the marble curile chairs, the official chairs of the two consuls, who acted as presidents of the House. Between them today stood a handsome chair of gold and ivory, the emperor’s chair, brought in earlier by Palatium staff. Here, too, were the Senate water clocks and their attendants. The clocks were elaborate devices of glass and wood that would mark the passing of the twelve hours of the Roman day, which began at dawn and ended at sunset, before the twelve hours of the night began. Roman water clocks were imprecise devices with floats descending in glass tubes as water seeped away, with the hours marked on the glass. The clocks served as a mere guide to the passing of time; to paraphrase a later saying, it was easier for all the water clocks of Rome to agree than for all its philosophers to agree, and even that would be something of a miracle.

Literate slaves were in place to note down every word said during the hearing, in Roman shorthand invented a century earlier by Tiro, secretary to the famous orator Cicero. The note-taking was for the official Senate record, the Acta Senatus, which would be kept in the Tabularium, Rome’s 152-year-old archives building, just a stone’s throw from the Senate House at the foot of the Capitoline Mount. That building is also still in existence today; the records, which would be consulted by later Roman historians including Tacitus, would not survive to modern times.

Julius Caesar had admitted as many as a thousand men to the Senatorial Order. Augustus had reduced the number to six hundred. With natural attrition, with forty or so senators absent commanding legions or governing provinces, and with others away on personal business or too infirm to attend, there were perhaps three hundred senators present for this, the most talked-about trial in Roman history. Germanicus’s adoptive brother, Drusus the Younger, was among those sitting in the front row. Drusus had hurried across the Adriatic to Rome from his Balkan posting to be present at the trial, forgoing his right to enter the city by taking the Ovation voted to him by the Senate the previous year (an Ovation awarded more to please Tiberius than to praise Drusus), supposedly for Drusus’s adept statesmanship when dealing with German tribes in a recent political crisis. According to Tacitus, Drusus looked genuinely sorrowful, as if the death of Germanicus had touched him deeply.

The three prosecutors in the Germanicus case were here, all close friends of Germanicus who had been with him at Daphne during his last hours and had taken his hand and promised to avenge him: Quintus Veranius, a former consul, the man appointed governorof Cappadocia by Germanicus and now in his forties; Quintus Servaeus, the former praetor appointed governor of Commagene by Germanicus, close to forty, the man who would become, or perhaps already was, a secret friend of Sejanus; and Publius Vitellius, former commander of the 2nd Augusta Legion in Germany and companion to Germanicus in the East, in his late thirties, a member of Rome’s illustrious Vitellius family. Of these three prosecutors, Vitellius had probably known Germanicus best, having fought beside him in campaign after campaign in Germany. He had seen Germanicus victorious at the Battle of Idistaviso, beside the Weser River, where Hermann’s army of fifty thousand warriors had been crushed. Vitellius had seen Germanicus personally lead the Praetorian Guard against the Germans in the Battle of the Angrivar Barrier, and had heard Germanicus’s firm command repeated through the ranks in the heat of that bloody, day-long battle: “Take no prisoners!” Vitellius knew that while Germanicus may have acted kindly toward his fellow Romans, against the enemies of Rome he could be inexorable. Just as Vitellius and his colleagues had expressed their determination to be inexorable with the murderer of the prince.

Gnaeus Piso was here, sitting on a front bench. His sons Gnaeus Jr. and Marcus sat on back benches with the junior senators, in all likelihood looking worried and almost certainly being avoided by other members of the House. The three advocates for the defense were present, taking their places on the front bench. Piso had experienced considerable trouble finding qualified, respected senators who would represent him. Six senators had turned him down when he approached them, before three men known to be close to the emperor had agreed to represent him. One was Lucius Calpurnius Piso, a relative of the defendant, who had served as a consul five years before; it appears that he had a good tactical mind, for he was reputedly an avid player of latrunculi, Roman chess. Another defense counsel was Livineius Regulus, a senator who would be made a consul by Tiberius. The third defense advocate was Marcus Lepidus Aemilius. Very rich, from the leading Aemilian family, and an able consul in A.D. 6, Lepidus was a man who possessed a “contemptuous indifference” to power, in the opinion of the late emperor Augustus, while Tacitus was to describe Lepidus as a wise and highly principled man.¹ Lepidus also was a close friend and firm favorite of Tiberius.

Piso himself seemed calm, composed, and self-assured as the day of his trial dawned. He had been comforted, says Tacitus, by the fact that his wife, Plancina, had sworn to stand by him and to share his lot, whatever might come, and in the worst event even to share death with him.¹¹ Not that Piso was contemplating losing this trial. He had received assurances from Praetorian prefect Sejanus that the emperor would look after him.¹² Besides, he had some insurance: anyone who looked closely would have seen a rolled document beside Piso on the Senate House bench. The significance of this document, which Piso would occasionally take up but never open during the trial, would later become apparent.¹³

Before any business could be done in the House, augurs, or Roman priests who were to interpret signs from the heavens, had conducted a ritual animal sacrifice, checking the slain animal’s entrails and certifying that they were clear, meaning the omens were consequently good for the sitting. The augurs also offered prayers to the gods for heavenly guidance for the senators in their deliberations. With those preliminary formalities out of the way, the senators now awaited the arrival of the emperor.

As dawn was breaking in the eastern sky, a herald bellowed an announcement. “Make way for the emperor!”

The senators fell silent and came to their feet as, preceded by his twelve lictors, official attendants in white robes and bearing his twelve fasces, Tiberius entered by the Senate House’s front door. Behind him, tall, bearded auxiliary soldiers, Batavians and Germans from today’s Holland and Germany, members of the emperor’s German Guard bodyguard, took up positions at the door, looking uncivilized in their breeches, long hair, and trimmed beards—at that time in Roman history, Roman citizens shaved every day from the time they came of age at the end of their fifteenth year, but German troops in the Roman army did not.

Sixty-year-old Tiberius was tall and well built. Bald now that he was beginning down the road to old age, he had large eyes and fine features. Extremely pimply as a youth, he still suffered from poor skin. He walked, says Suetonius, with a stiff gait, and with his head poked forward.¹ Praetorian prefect Lucius Sejanus, a powerfully built man who affected a humble air, walked in the emperor’s shadow, with several freedmen secretaries bustling along close behind. Tiberius walked down the center of the House to his raised chair, from where, with his staff arrayed behind him, he bade the senators resume their seats. Sejanus, now that Tiberius had granted him the rank of a praetor, also took his seat among the senators.

The doors around the Senate House walls were now all closed. Attendants would open them to allow senators to come and go as they slipped out to relieve themselves or to grab something to eat or drink as the day drew out, for Senate sittings went on without interruption until the sun went down. To learn how the trial was faring inside, the huge crowd outside would have to wait for word to be brought out to them by the coming and going senators, and many a senator would use the opportunity to make himself sound important as he regaled the crowd with the latest news from inside as the trial heated up.

With nervous coughs echoing around the chamber, Tiberius sought and received permission from the president of the House, Aurelius Cotta, the senior current consul, to address the honorable senators. As the emperor came to his feet, a secretary handed him a scroll containing a prepared speech. Tiberius was fluent in Greek as well as Latin, but, unlike other Roman leaders before him, including Julius Caesar, Tiberius preferred not to use Greek but addressed the Senate in Latin, the Roman tongue. He would go to great lengths to exclude even widely used Greek terms from his speeches. Both Caesar and Augustus had been excellent public speakers, but despite years of training as a youth and much practice since, Tiberius was not. He read this speech to the House in his usual slow and methodical manner.

“Senators, Piso was the representative and friend of my father [Augustus],” he began. “On the advice of the Senate, I appointed him to assist Germanicus in the administration of the East.” In reality, the Senate had not had any influence in Piso’s appointment. The emperor’s gubernatorial appointments were always submitted to the Senate for rubber-stamping. In practice, the Senate always advised the emperor that it approved of his choice of governor. “It is for you to determine, with unbiased minds,” Tiberius went on, “whether he provoked the young prince there through rivalry and willful opposition, whether he rejoiced at his death, whether he wickedly ended his life.

“Certainly, if a subordinate goes beyond the bounds of duty and beyond the bounds of obedience to his superior, and has been delighted by his death, and by my pain, I will despise him, and exclude him from my house. But I will avenge a personal wrongwithout resorting to my power as emperor. However, if it is found that a crime has been committed that should be punished, no matter who the murdered man is, it is for you to deliver just compensation to the children of Germanicus, and to us, his parents.

“Also consider this. Did Piso deal with the legions in a seditious, revolutionary manner? Did he seek popularity with the troops by underhand means? Did he attempt to retake the province of Syria using armed force? Or are these all fabrications put about by his accusers? As for those accusers—” he glanced briefly at the three prosecutors— “I am angry with their unrestricted zeal. Why did they strip Germanicus’s corpse and expose it to the vulgar gaze, and circulate among foreigners the tale that he had been killed with poison, if this is all still doubtful and needs investigating?”

He paused, allowing his comments to sink in, before continuing. “Personally, I lament my son’s death and always will. Yet, I wouldn’t prevent the accused from producing any evidence that can prove his innocence or convict Germanicus of any unfair acts, if there were such acts. And I beg you not to take alleged charges as proven simply because this case is intimately linked with my loss.”

He looked at Piso’s three defenders. “You, whom blood ties or good hearts have made his advocates, help the accused in his time of peril, every one of you, to the full extent of your eloquence and diligence.” He turned to the prosecutors. “I would urge the prosecutors to similar exertions and persistency.”

Again he addressed the House as a whole. “In this, and in this alone will we place Germanicus above the laws, by conducting the inquiry into his death in this House instead of in the Forum, before the Senate rather than before a bench of judges. In every other respect let this case be tried as simply as any other. I want none of you to be influenced by Drusus’s tears or by my own sorrow, nor by any stories you may hear that have been invented to discredit us.”¹

With that, the emperor took his seat, nodding to the consul Cotta, who then invited the prosecution to begin. But before Vitellius, Servaeus, or Veranius could open their mouths, Fulcinius Trio jumped up and was recognized by the consul. To the frustration of the prosecutors and many others in the chamber, Trio proceeded to level his irrelevant accusations against Piso, claiming that he had been involved in secret schemes and extortion of provincials when he had served as governor of one of the Spanish provinces during the reign of Augustus. This seemed designed to waste the valuable time allocated to the prosecution, but the consul allowed Trio to expand on his allegations. Whether this was Trio’s own contrivance, merely to win favor with Tiberius, or whether he had been put up to it by either Tiberius or Sejanus, we will never know. But he would later be among Sejanus’s closest associates, eventually gaining a consulship via Sejanus’s influence. By the middle of the day, after depriving the legitimate prosecution of precious hours, Trio finally completed his submission to the House and sat back down.

At last, a murder prosecution against Piso could commence. The prosecutors had to overcome several early hurdles. For one thing, there was Trio’s time-wasting. Then there was Tiberius’s insistence that he considered Piso innocent until proven guilty. In fact, the emperor’s opening address had seemed to favor the accused. But worse than this, a key prosecution witness would not be appearing. Despite being kept under close guard at Brindisi, Martina, the Syrian maker of poisons, had been found dead in her quarters. Her body showed no sign of either murder or suicide, but a vial of unused poison had been found in a knot of her hair. Some would assume that she had used a second vial to kill herself, although no second, empty vial was located. Others would wonder if one of her guards had not poisoned her. No proof would emerge either way. Because no testimony had been forthcoming from Martina while she was alive—a written statement could not legally be presented in court, but witnesses could testify to what Martina had told them, if she had told them anything—the prosecution had to proceed without the one witness who might have shone light on how Germanicus died, and who could possibly have linked Plancina and/or Piso to the crime.

It was with these limitations that the prosecution of Piso, his wife, and his son began.

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